高壓下에서 電池 Pb(Hg)|PbX_2(m), AgX(s)|Ag(X=Cl, Br, I) 및 Hg|Hg_2Cl_2(s)KCl(m), AgCl(s)|Ag의 起電力과 그의 熱力學的 性質

黃正儀,池鍾基 慶北大學校 産業開發硏究所 1975 硏究報告 Vol.3 No.-

Appling the complete quilibrium constant to the electro-cell reaction, it was derived that the standard electromtive force of the cell at high pressure(1―2, 500 bars). This theory was briefly discussed and applied to some cells such as, Pb|PbX_2(m), AgX(s)|Ag(X=Cl, Br and I)and Hg|Hg_2Cl_2(s), KCl(m), AgCl(s)|Ag. The results were conterminous as the previous results which applied to some other cells i.e. the electromotive force of the cells were increased as the pressure and temperaure increase except the PbCl_2 cell. The net change of the hydration number of the cell reaction were 26.1 for PbCl_2, 23.5 for PbBr_2 and 26.9 for PbI_2 cell, respectively. From the k-values the standard electromotive force and some other related thermodynamic values were calculated.

電氣的 開始法에 의한 2-Hydroxyethyl methacrylate의 重合과 이들 膜의 電氣的 性質

黃正儀,鄭倧在,車星極 慶北大學校 1978 論文集 Vol.25-26 No.-

The electroinitiated polymerization of 2-hydroxy ethyl methacrylate (HEMA) has been studied at the various voltages, from 2 to 2500 volts. The rate of polymerization was increased with increasing voltages. It was supposed that the orientation and migration effect of monomer accelerating the rate. The membranes were molded between two separated glass plates. These membranes have been used to measure the membrane potentials and the transport number of Na^+ ion and water. The measured membrane potentials and calculated values, which were related by Scatchard theory, gave satisfactory agreement below 0.1m. This was due to permselectivity of HEMA membranes, which had high fixed-OH group in the pore as a pendent. The main deviations of measured membrane potentials (E_c) and the maximum possible values of electrical potentials (E_max) were due to transport numbers of Cl^-ion and water. Therefore it seems to be make an useful strong hemodialysis HEMA membranes by electroinitiated grafting polymerization.

고압하에서 혼합용매중의 몇가지 염의 전도도

황정의,오상오 慶北大學校 自然科學大學 1987 自然科學論文集 Vol.5 No.-

The equivalent conductance of magnesium chloride and magnesium sulfate soulutions have been measured at different pressures and temperatures varying the solvent composition of components. The conductances of most solutions were increased with increasing pressure but the values of MgCl_2 were decreased in the high alcohol content. The phenomenon indicate that the solvent separated ion effect is predominant in magnesium sulfate solution than in magnesium chloride or sodium chloride which shows the lower conductivities at the higher pressure. The activation energies for the eletrical conductance were remained in constant value of 2∼3 Kcal/mole. The ionization constants of salts were calculated from the conductivity data and physical properties by using the Shedlovsky's equation. The K_d values for magnesium sulfate varied in the range of 1.0×10^-3∼9.0×10^-3 at 20℃. These values are comparable with the values of 1∼10 for sodium chloride at 100℃. These abnormally large values are explained as the results of higher charge and lower temperature effect of magnesium salt than sodium salt. From the concept of the complete ionization constant the hydration number change is also calculated to be 8. 5. This value is slightly different from the sodium chloride.

니켈-카드뮴 蓄電池중의 니켈極의 特性에 미치는 電解質의 影響

黃正儀,鄭倧在,金昌鎬 慶北大學校 自然科學大學 1986 自然科學論文集 Vol.4 No.-

Properties of the Ni(OH) electrode in Nickel-Cadmium battery are studied by the cyclo-voltammetric method in base solutions (LiOH, NaOH, KOH)at 20℃. The nickel electrode was prepared chemical precipitation of Ni(OH)_2 on the conducting substrate. The redox current ratio(ipa/ipc) which is closely related to the charge ratio of the Ni(OH)_2 electrode is greater than unity. We can conclude that OH^-ions have been inserted into the Ni(OH)_2 intersheets or adsorbed on the Ni(OH)_2 layers. The electrooxidation of inserted or adsorbed OH^- ions can be explained through a catalytic process involving the participation of Ni(Ⅱ)→Ni(Ⅲ) electrochemical reaction. The reaction products such as (OH) or OH^- also were retained in the defects of Ni(OH)_2 crystalline layers. The redox current ratio is increased by the existence of molecular oxygen in the electrolyte, because the number of OH^- ion in IHP may be increased by reduction of molecular oxygen. Voltammograms run in LiOH solutions are comparable to those recorded in NaOH or KOH solutions. In the same perturbation conditions, redox current ratio related to the Ni(Ⅱ)/Ni(Ⅲ) redox couple values in LiOH are greater than those obtained in NaOH or KOH. The effect of LiOH solution may be ascribed to the presence of highly solvated cations Li^+. In order that OH- ions can be closely adsorbed on the electrode surface, chemical work must be done to take off some water molecules from its primary hydrated sheath. It is guessed that solvated cations take up these chemical works. The sequence of redox current ratio is Li^+>Na^+>K^+.

Cupferron의 전극반응기구(제Ⅱ보)

黃金小,鄭倧在,黃正儀 釜山水産大學校 1976 釜山水産大學 硏究報告 Vol.16 No.1

In Previous paper polarographic and chronopotentiometric analysis of electrde reducction mechanism of cupferron in neutral and alkline media was mentioned. The electrode reaction mechanism was discussed in the aspects of current/electrode potontial and Vetter-Enyo's reaction order method in this experiment. from the results, it was reaffirmed that the electrode process of cupferron in alkaline aqueous solution is the ECE (charge transfer-chemical reaction-charge transfer) mechanism. The result of a technique of current/electrode potential showed the chemical reaction step of intermediate reactant was reversible and the rate determining step. Besides various parameters obtained in the experiment were also described.

안티몬 전극을 이용한 고압하에서 용액의 pH측정

黃正儀,鄭倧在,車星極 慶北大學校 文理科大學 1978 文理學叢 Vol.5 No.-

The stick antimony electrode has advantage of simplicity in measuring pH. Its field of application has been very wide in industrial and medical part. But its accuracy, sensitivity and reproducibility are somewhat poorer than those of glass electrode. In this study this electrode was applied in determining pH of the solution at various temperatures (15∼30℃) under high pressures (1∼2,500 bars). The emf(E) of the cell, Sb(Sb_2O_3/ HCl(aq.) /AgCl/ Ag, was messured and plotted against pH. In this plot standard emf(E°) of the cell was obtained by extrapolation. The relationship of emf(E) and pH at 25℃ under 1 bar was as follows, E=0.034+0.05918 pH. The slopes were decreased with increasing pressure, and emf(E) was increased. These phenomena may be caused to the activities of water, Cl^-, Sb_2, Sb_2O_3, Ag, and AgCl. In plot of pressure and pH the decrease of pH values was due to the increase of dissociation constant of hydrochoric acid. Even though the stick antimony electrode could be useful to 500 bars at 30℃, it could be useful to 1000 bars below 30℃.

에탄올-물 혼합용매내에서 2,4,6,N-Tetramethyl Pyridinium Iodide의 회합에 대한 압력효과

黃正儀,池鍾基,李永華,禹義夏 慶北大學校 物理化學硏究所 1984 硏究論文集 Vol.5 No.-

부피 퍼센트 95%의 에탄올-물 혼합용매내에서 2,4,6,N-테트라메틸 피리디늄요오드(TeMPI)의 이온회합 상수(K)를 수정한 자외선분광 및 전기 전도도 혼용법으로 온도범위 25∼50℃, 압력범위 1∼2,000bars에서 결정하였다. K값은 압력이 증가함에 따라서 증가하였고 40℃에서 최대값을 나타내었다. 부분몰부피변화(ΔV)는 비교적 작은 음의 값이 었으며 ΔV의 절대값은 40℃에서 최소값을 보여주었다. TeMPI의 이온 크기 변수(a)는 40℃에서 최대값을 가졌다. ΔH˚값은 40, 25℃ 그리고 50℃에서 각각 영, 음수 및 양수로 나타났으며 엔트로피(ΔS˚)와 자유에너지(ΔG˚)와 같은 다른 열역학변수 값도 계산하였다. 이와 같은 실험결과로부터 우리들은 TeMPI가 압력증가에 대하여 안정화되고, 40℃까지는 온도증가에 따라서도 안정화됨을 보여주었다. 그러나 40℃에서는 TeMPI 두 분자에 있는 8개 메틸기의 분자간 소수성 상호작용으로 인하여 약한 이량체를 형성하고 50℃ 이상에서는 다시 열적으로 분해된다는 결론을 얻게 되었다. The ionic association constants(K) of 2,4,6,N-tetramethyl pyridinium iodide(TeMPI) in 95 volume percentage ethanol-water mixture were determined by a modified UV and conductance method at 25℃ to 50℃ under 1 to 2,000 bars. The K values increase with increasing pressure and have maximum value at 40℃. The partial molar volume change (ΔV) has relatively small negative value and the absolute values of Δ are minimum at 40℃. The ion size parameter(a) of TeMPI have maximum value at 40℃. ΔH˚ values are zero, positive and negative at 40℃, 25℃ and 50℃ respectively. Other thermodynamic parameters such as the changes of standard entropy (ΔS˚) and free energy(ΔG˚) were evaluated. From these experimental results, we came to conclusion that TeMPI is stabilized by the elevation of pressure and that of temperature below 40℃ but weakly dimerized at 40℃ because of the intermolecular hydrophobic interaction of eight methyl groups of two molecules. And it thermally decomposed above 50℃.

염화아세트산들의 해리반응에 미치는 온도와 압력의 영향

황정의,정종재,박용태,지종기,박의환 慶北大學校 1982 論文集 Vol.33 No.-

The temperature and pressure dependences of the dissociation constants of mono-, di- and tri-chloroacetic acids were studied by the conductimetry in the range of 20-35℃ and 1-2500 bars. The thermodynamic parameters ΔH, ΔS, and ΔV were evaluated from the dissociation constants. The dissociation constants were increased as the temperature and pressure was increased respectively. The pressure effects can be explained by the fact that the increase of the charges of reaction species enhances the solvation of ions and reduces the reaction volume. As the more chlorines were substituted to acetic acid, the effect of pressure on the dissociation constants was decreased because of the enhanced solvation effect. From the thermodynamic data it can be estimated that there are two types of dissociation reactions. They are an enthalpy-dominated reaction and an entropy-dominated one.

분광광도법에 의한 3-Chloro 및 3-Bromopyridine의 해리상수 측정과 그의 온도와 압력에 따른 영향

黃正儀,鄭倧在,尹永炷,金學成 慶北大學校 1984 論文集 Vol.38 No.-

Pyridine and most of substituted pyridines react as base in aqueous solutions. Strength of their basicities can be represented quantitatively by the dissociation constant of a base or its conjugated acid. The dissociation constants of weak acid or base are highly dependent on the pressure and the temperature. The dissociation constants of these substituted pyridines have been reported only under the pressure of atmosphere but not high pressure. In this study, we measured the dissociation constants of 3-chloro and 3-bromopyridine under high pressure by the method of spectrophotometry. Also, we obtained the thermodynamic parameters on the dissociation reactions that show the effects of the temperature and the pressure on the dissociation constants.

백금전극에서 진한 염소산이온의 음극환원기구에 관한 연구

黃正儀,黃金小 慶北大學校 文理科大學 1974 文理學叢 Vol.2 No.-

The mechamisms of the anodic oxidation and the cathodic reduction of chlorate ion were investigated, using Pt-electrode, by means of a technique of galvanostatic double pulses. The electrode potential exhibited sharp increase in the potential-tine curve-by applying first on anodic pulse at the current density, 15 and 60ma/㎠. Th seems due to the oxidation of ClO^-_3 to CIO^-_4 After applying anodic pulse which allowed constant potential, the two transition times, τ_1 and τ_2, could be detected by applying cathodic pulse. Furthermore, the obtained transition times allowed to calculated the ratios of the number of the electron related to a cathodic reduction and to propose the possible mechanisms as well. It was found that the electrode reduction processes of chlorate ion and perchlorate ion were different from those reported by others lately.